Question: Rewrite ${((4^{-9})(9^{-7}))^{-9}}$ in the form ${4^n \times 9^m}$.
Solution: ${ ((4^{-9})(9^{-7}))^{-9} = (4^{(-9)(-9)})(9^{(-7)(-9)})} $ ${\hphantom{ ((4^{-9})(9^{-7}))^{-9}} = 4^{81} \times 9^{63}} $